Ni-based multi-interface engineering on MXene (Ti₃C₂T_x) modified electrode for all-pH-value hydrogen evolution

The research of electrocatalysts with high efficiency and stability towards hydrogen evolution reaction (HER) in all-pH-value plays a vital role in advancing clean energy development, while it is still a huge challenge. In this article, Ni3S2 was effectively attached to the surface of MXene-modified nickel foam (NF) (Ni3S2@ MXene/NF) using an electrodeposition method, resulting in loose flower-like structures with a larger surface area. Furthermore, the concentration of electrolyte solution affects the catalytic performances. Impressively, the optimized Ni3S2@MXene/NF shows remarkable HER performances in 0.5 M H2SO4, 1 M KOH, and 1 M PBS (pH = 7), demanding overpotentials of 239, 172, and 94 mV to attain 30 mA cm-2 with excellent stability, respectively. The results from in-situ X-ray diffraction (XRD) revealed that stability is determined by the crystal planes of (020), (120), and (221) in a neutral solution. Furthermore, density functional theory (DFT) showed that the multi-interface engineering is constituted by the combination of MXene and Ni3S2, which can maximum optimize the free energy of the catalyst surface adsorption of H2O and H* within a wide pH range. This research presents a pioneering approach to catalyst modification for enhancing hydrogen production efficiency in all-pHvalue electrolyte.